The majority of terrestrial plants live in association with symbiotic microorganisms, such as fungi which facilitate their access to soil nutrients. The ectomycorrhizal (ECM) symbiosis is the most common association in forest under boreal and temperate climates. Plants harbor a diverse array of asymptomatic fungal foliar and root endosymbionts and have been recovered from all examined plant taxa to date. Several native endophytic and mycorrhizal fungi have been isolated and characterized as promoter of plant host growth and productivity. Concomitantly native bacterial isolates having a plant growth promoting effect and enhancing the fungal-plant beneficial interaction have been characterized as well.
Populus is a dominant perennial component of temperate forests having the broadest geographic distribution of any North American tree genus, and is a woody perennial model with high value in pulp, paper and biofuel industries. Populus is cultivated worldwide for pulp and paper, veneer, packing material, engineered wood products (e.g., oriented strand board), lumber, and has recently emerged as the preeminent fast-growing woody crop for bioenergy research. Populus can be grown on economically marginal agricultural land thereby minimizing the competition between food and fuel production. Moreover, Populus is known to associate with a wide variety of root symbiotic microbes. Populus is also one of the few plants known to be colonized by both endo- and ectomycorrhizal fungi, making it a unique model system for the study of interactions between plants and microorganisms.
Corn (Zea mays, also known as maize) is the most widely grown grain crop throughout the Americas, and a food crop model for bioethanol production in the United States.
The symbiotic fungus Laccaria bicolor is a member of Hydnangiaceae (Basidiomycota, Agaricomycotina, Agaricomycetes, Agaricomycetidae, Agaricales), a large family of ectomycorrhizal and saprotrophic basidiomycetes. Piriformospora indica (Hymenomycetes, Basidiomycota) is a cultivable endophyte that colonizes roots.
The symbiotic fungus Hebeloma is a member of Hymenogastraceae (Basidiomycota, Agaricomycotina, Agaricomycetes, Agaricales, Hymenogastraceae), a large family of ectomycorrhizal and saprotrophic basidiomycetes with a wide range of tree-hosts, and can be found in most woodland ecosystems worldwide. The symbiotic fungus Cenoccocum is an ascomycetous fungus placed into the Dothideomycetes, where it represents the only known ectomycorrhizal species within this large and ecologically diverse class of Ascomycota. It is one of the most common and globally abundant genera of ectomycorrhizal fungi, forming black ectomycorrhizas with darkly pigmented hyphae. It has a broad host- and habitat range.
Microbial pathogens, like Atractiella (Atr) and Neonectria, are detrimental to plant growth. Effective and eco-friendly ways are needed to combat pathogenic microorganisms. Currently the chemical compounds to combat pathogens are also damaging to the environment and possibly human health. The current invention offers a solution with a composition made up of benign and natural microorganisms.
Another important aspect of plant growth is the ability to adapt to arid or drought conditions, which is a trait known as drought tolerance/resistance. Arid conditions can lower the yield of many crops, causing great financial losses. Therefore, methods to increase drought tolerance/resistance in plants are needed. The symbiotic microorganism compositions disclosed herein help plants tolerate dry conditions better.